Step 3: Put it together

Step 4: Try it out

Fill up some water balloons. Then, tie the ends of the tubing (they should both be on the same side) to a tree, pole, or anything else that is secure...

Make a wicked cool catapult that shoots water balloons really well without them exploding right away! You can buy water balloon shooters in stores, but they never work well and explode the water balloon as soon as you let go.

Step 1: Gather materials

You will need an old towel, or some sort of rag that you can cut up. You will also need a length of surgical tubing, exercise tubing will work here as well. Lastly, you will need two small scraps of wood and some duct tape. You will also need scissors to cut the rag.

Step 2: Cut the pattern for the rag

The rag will become the pocket for the water balloon. It should be cut in a big "+" pattern. So, make a big 14" by 14" (it doesn't need to be perfect) square and cut out 3" by 3" pieces from the corners. You will want two of the tabs to be able to fold over the wood, so plan accordingly.

Step 3: Put it together

Lay a piece of wood on one of the tabs. Then fold the rag over the wood and wrap the duct tape around it so the wood is stuck inside. Repeat for the opposite side and the other piece of wood.

Next, lay out the surgical tubing so that it runs over one of the other two tabs. Then curve it 180 degrees so that it runs down the other side of the rag. Once again, tape the rag over the tubing. Make sure you don't actually tape the tubing so that the pocket can slide freely up and down the tubing. Tape all of the corners and seams to reinforce them. You can not have to much tape on this project.

na, that prolly wouldnt work, unless you have reeaally good rubber bands theyre prolly gonna snap pretty fast, i made a slingshot about 6 ft tall that shot pebbles about 150 ft using rubber bands, they snapped after 50 uses or sumthing like that, so i dont suggest it.

@backyardpyro217 that's because, assuming that they launched the balloon at less than the balloon's terminal velocity, the balloon would be going roughly the same speed at which it was launched when it landed.

Instead of the rag and duct tape pocket to hold the water balloon in, i used the top half of a coke bottle, and just roll the cut edge to stop the edge cutting the balloon and it strengthens the cup ring to attach the bungie cord to. Drill holes through the threaded end and thread a some cord through it to make a loop to pull back the balloon cup. These work awesome.

what about grenades and molotovs? MUAHAHAHAHAHAHA! i actually know a guy who made this with a few of his buddies, they were able to launch a water balloon about two blocks and still take out a window XD

Aircraft carriers use catapults to launch planes... Some roller coasters use catapults (just about anything that adds momentum without a chain lift)... A trebuchet also happens to be a type of catapult... Even a crossbow is technically a catapult :P

It doesn't say in those definitions (they are somewhat cursory - although the princeton one alludes to this by saying a "heavy" engine), but generally catapults have to not be handheld devices, so not a crossbow (which agrees with our gut feelings that a crossbow is kind of a silly thing to call a catapult - and also the fact that nobody ever calls them that in practice).

I guess you missed the big discussion on this matter last month. A slingshot is something that you swing around (i.e. David and Goliath) and release shot out of. What we call slingshots are actually types of catapults.

Actually...the david and goliath story used a SLING, which was simply a pouch at the end of 2 cords... similar to the slingshot, but still quite different. Sling: Pouch, 2 cords, uses whirling action for propulsion Slingshot: Pouch, 2 rubberized cords connected between the pouch and a forked shape, uses stretchability for propulsion.

Too true. Also, both slings and slingshots typically would be handheld too, making them not catapults. Since this is tied to a tree, it probably qualifies as a catapult (though possibly still also a slingshot. The two can overlap)

I have a store bought one, and it works fine, never had any problems with it. Also, if you tie one end to something, in my experience with multiple launchers, there is a good chance that the balloon won't leave the pouch and will come back at you. I highly recommend having to friends hold the ends of tubing much better and actually safer.